A woman smokes marijuana during the annual 4/20 marijuana rally on Parliament Hill in Ottawa, Ontario, Canada, April 20, 2017. (Photo by Chris Wattie/Reuters)

The entire cast perform during a production media call for Singin' In The Rain at Her Majesty's Theatre on May 12, 2016 in Melbourne, Australia. (Photo by Robert Cianflone/Getty Images)

Ng Sin Nee (L) and Lee Shin May (R) from Malaysia take pictures with the panoramic view of the city from the Sky Box at KL Tower, the world's seventh tallest telecommunications tower, in Kuala Lumpur on May 24, 2016. Officially opened on May 20, the Sky Box has been the latest attraction for tourists arriving to the Malaysian capital. It stands 300 metres above ground and can fit six people at any one time, and offers spectacular views of the Kuala Lumpur skyline, including the iconic Petronas Twin Towers. (Photo by Mohd Rasfan/AFP Photo)

Mahouts return home with their elephants carrying grass to feed them on the eve of the rhino census in Kaziranga National Park in Assam state, India, 24 March 2015. Kaziranga will be closed to visitors for the next two days for a census of the rhinos commencing 25 March, in a previous census in 2013 in the park the population of the Indian rhinos was 2329. (Photo by EPA/Stringer)

In this Tuesday, March 31, 2015 photo, Indian women walk carrying firewood they collected from a forest at Gobhali village on the outskirts of Gauhati, India. Every evening, hundreds of millions of Indian women hover over crude stoves making dinner for their families. They feed the flames with polluting fuels like kerosene or cow dung, and breathe the acrid smoke wafting from the fires. (Photo by Anupam Nath/AP Photo)

Amphibious assault vehicles of the South Korean Marine Corps throw smoke bombs as they move to land on shore during a U.S.-South Korea joint landing operation drill in Pohang March 31, 2014. The drill is part of the two countries' annual military training called Foal Eagle, which began on February 24 and runs until April 18. (Photo by Kim Hong-Ji/Reuters)

In this Sunday, April 27, 2014 handout photo provided by Busch Gardens Tampa, mother armadillo Zowie, left, welcomes her newborn Southern three-banded armadillo baby at the Animal Ambassador Team, in Tampa, Fla. The baby was able to walk and roll into a ball within moments of its birth. Southern three-banded armadillos are the only species of armadillo that can fully roll up into a ball. (Photo by AP Photo/Busch Gardens Tampa)

People ride a motorcycle near Koudoukou Mosque where Pope Francis meets Imam Tidiani Moussa Naibi in Bangui, Central African Republic, November 30, 2015. (Photo by Stefano Rellandini/Reuters)